scholarly journals Ionization effect of solar particle GLE events in low and middle atmosphere

2010 ◽  
Vol 10 (12) ◽  
pp. 30381-30404 ◽  
Author(s):  
I. G. Usoskin ◽  
G. A. Kovaltsov ◽  
I. A. Mironova ◽  
A. J. Tylka ◽  
W. F. Dietrich
Keyword(s):  
Middle Atmosphere ◽  
Ground Level ◽  
Solar Proton ◽  
Energy Spectra ◽  
Wide Energy Range ◽  
Ground Level Enhancement ◽  
Direct Ionization ◽  
Ionization Effect ◽  
The World ◽  
Wide Energy

Abstract. Using a new reconstruction of the solar proton energy spectra for Ground Level Enhancement (GLE) events, based on fits to measurements from ground-based and satellite-borne instruments covering a wide energy range, we quantitatively evaluate the possible ionization effects in the low and middle atmosphere for 58 out of the 66 GLE events recorded by the world-wide neutron monitor network since 1956. The ionization computations are based on the numerical 3-D CRAC:CRII model. A table of the ionization effect caused by the GLE events at different atmospheric heights is provided. It is shown that the direct ionization effect is negligible or even negative, due to the accompanying Forbush decreases, in all low- and mid-latitude regions. The ionization effect is important only in the polar atmosphere, where it can be dramatic in the middle and upper atmosphere (above 30 km) during major GLE events.

scholarly journals Ionization effect of solar particle GLE events in low and middle atmosphere

2011 ◽  
Vol 11 (5) ◽  
pp. 1979-1988 ◽  
Author(s):  
I. G. Usoskin ◽  
G. A. Kovaltsov ◽  
I. A. Mironova ◽  
A. J. Tylka ◽  
W. F. Dietrich
Keyword(s):  
Middle Atmosphere ◽  
Ground Level ◽  
Solar Proton ◽  
Energy Spectra ◽  
Wide Energy Range ◽  
Ground Level Enhancement ◽  
Direct Ionization ◽  
Ionization Effect ◽  
The World ◽  
Wide Energy

Abstract. Using a new reconstruction of the solar proton energy spectra for Ground Level Enhancement (GLE) events, based on fits to measurements from ground-based and satellite-borne instruments covering a wide energy range, we quantitatively evaluate the possible ionization effects in the low and middle atmosphere for 58 out of the 66 GLE events recorded by the world-wide neutron monitor network since 1956. The ionization computations are based on the numerical 3D CRAC:CRII model. A table of the ionization effect caused by the GLE events at different atmospheric heights is provided. It is shown that the direct ionization effect is negligible or even negative, due to the accompanying Forbush decreases, in all low- and mid-latitude regions. The ionization effect is important only in the polar atmosphere, where it can be dramatic in the middle and upper atmosphere (above 30 km) during major GLE events.

scholarly journals GLE events in 24th solar cycle

2018 ◽  
Vol 62 ◽  
pp. 01006
Author(s):  
Yury Balabin ◽  
Boris Gvozdevsky ◽  
Aleksei Germanenko ◽  
Eugeny Maurchev
Keyword(s):  
Solar Cycle ◽  
Cosmic Rays ◽  
Ground Level ◽  
Energy Spectra ◽  
Special Technique ◽  
Neutron Monitors ◽  
Ground Level Enhancement ◽  
Solar Cosmic Rays ◽  
The World ◽  
Current Cycle

Started in 2009, the 24th solar cycle is going to end. In 2015, the solar activity was at its maximum, turning down. According to many indices, this cycle turned out to be abnormal. For instance, in the previous, the 23rd cycle, the index such as the number of solar spots was as high as 175, compared with that of the 24th cycle, not exceeding 100. According to the number of GLE-events (ground level enhancement of solar cosmic rays, observed on neutron monitors), the current cycle also differs greatly from the previous ones. In the 23rd cycle, the number of great GLE-events was as high as four, and that of small and moderate being five. In the 24th cycle, only two GLE-events were recorded: GLE 71 (17.05.2012) и GLE 72 (10.09.2017), with the last event being of small amplitude (5%). The presence of the neutron monitors network data enables calculation of the energy spectrum and other parameters of solar cosmic rays. The GLEevents are processed by special technique developed at PGI. It is aimed at solving the inverse problem: based on the data from the world neutron monitors network, to obtain the parameters of solar cosmic rays energy spectra. Like the previous ones, GLE-events 71 and 72 were processed by this technique. The energetic spectra obtained were compared with those in other events of the previous cycles

scholarly journals The event of ground level enhancement of solar cosmic rays on October 28, 2003: the spectrum in a wide energy range.

2016 ◽  
Author(s):  
Petr Yurievich Gololobov ◽  
Vladislav Grigoryev ◽  
Sergey Starodubtsev ◽  
Sergey Taneev ◽  
Germogen Krymsky
Keyword(s):  
Cosmic Rays ◽  
Energy Range ◽  
Ground Level ◽  
Wide Energy Range ◽  
Ground Level Enhancement ◽  
Solar Cosmic Rays ◽  
Wide Energy

scholarly journals Short- and Medium-Term Induced Ionization in the Earth Atmosphere by Galactic and Solar Cosmic Rays

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Alexander Mishev
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Ground Level ◽  
Galactic Cosmic Rays ◽  
Earth Atmosphere ◽  
Medium Term ◽  
Ground Level Enhancement ◽  
Solar Cosmic Rays ◽  
The Earth ◽  
Ionization Effect

The galactic cosmic rays are the main source of ionization in the troposphere of the Earth. Solar energetic particles of MeV energies cause an excess of ionization in the atmosphere, specifically over polar caps. The ionization effect during the major ground level enhancement 69 on January 20, 2005 is studied at various time scales. The estimation of ion rate is based on a recent numerical model for cosmic-ray-induced ionization. The ionization effect in the Earth atmosphere is obtained on the basis of solar proton energy spectra, reconstructed from GOES 11 measurements and subsequent full Monte Carlo simulation of cosmic-ray-induced atmospheric cascade. The evolution of atmospheric cascade is performed with CORSIKA 6.990 code using FLUKA 2011 and QGSJET II hadron interaction models. The atmospheric ion rate is explicitly obtained for various latitudes, namely, 40°N, 60°N and 80°N. The time evolution of obtained ion rates is presented. The short- and medium-term ionization effect is compared with the average effect due to galactic cosmic rays. It is demonstrated that ionization effect is significant only in subpolar and polar atmosphere during the major ground level enhancement of January 20, 2005. It is negative in troposphere at midlatitude, because of the accompanying Forbush effect.

THE GROUND-LEVEL ENHANCEMENT OF 2012 MAY 17: DERIVATION OF SOLAR PROTON EVENT PROPERTIES THROUGH THE APPLICATION OF THE NMBANGLE PPOLA MODEL

2014 ◽  
Vol 785 (2) ◽  
pp. 160 ◽  
Author(s):  
Christina Plainaki ◽  
Helen Mavromichalaki ◽  
Monica Laurenza ◽  
Maria Gerontidou ◽  
Anastasios Kanellakopoulos ◽  
...  
Keyword(s):  
Ground Level ◽  
Solar Proton ◽  
Solar Proton Event ◽  
Proton Event ◽  
Ground Level Enhancement

scholarly journals Radiation dose of aircrews during a solar proton event without ground-level enhancement

2015 ◽  
Vol 33 (1) ◽  
pp. 75-78 ◽  
Author(s):  
R. Kataoka ◽  
Y. Nakagawa ◽  
T. Sato
Keyword(s):  
Radiation Dose ◽  
Solar Energetic Particle ◽  
Ground Level ◽  
Solar Proton ◽  
Significant Enhancement ◽  
Radiation Hazard ◽  
Proton Event ◽  
Ground Level Enhancement ◽  
Air Shower ◽  
Open Question

Abstract. A significant enhancement of radiation doses is expected for aircrews during ground-level enhancement (GLE) events, while the possible radiation hazard remains an open question during non-GLE solar energetic particle (SEP) events. Using a new air-shower simulation driven by the proton flux data obtained from GOES satellites, we show the possibility of significant enhancement of the effective dose rate of up to 4.5 μSv h−1 at a conventional flight altitude of 12 km during the largest SEP event that did not cause a GLE. As a result, a new GOES-driven model is proposed to give an estimate of the contribution from the isotropic component of the radiation dose in the stratosphere during non-GLE SEP events.

scholarly journals Northern Hemisphere atmospheric influence of the solar proton events and ground level enhancement in January 2005

2011 ◽  
Vol 11 (3) ◽  
pp. 7715-7755 ◽  
Author(s):  
C. H. Jackman ◽  
D. R. Marsh ◽  
F. M. Vitt ◽  
R. G. Roble ◽  
C. E. Randall ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Atmospheric Chemistry ◽  
Reasonable Agreement ◽  
Climate Model ◽  
Michelson Interferometer ◽  
Ground Level ◽  
Solar Proton ◽  
Ground Level Enhancement ◽  
Time Period ◽  
Solar Proton Events

Abstract. Solar eruptions in early 2005 led to a substantial barrage of charged particles on the Earth's atmosphere during the 16–21 January period. Proton fluxes were greatly increased during these several days and led to the production of HOx (H, OH, HO2) and NOx (N, NO, NO2), which then caused the destruction of ozone. We focus on the Northern polar region, where satellite measurements and simulations with the Whole Atmosphere Community Climate Model (WACCM3) showed large enhancements in mesospheric HOx and NOx constituents, and associated ozone reductions, due to these solar proton events (SPEs). The WACCM3 simulations show enhanced short-lived OH throughout the mesosphere in the 60–82.5° N latitude band due to the SPEs for most days in the 16–21 January 2005 period, in reasonable agreement with the Aura Microwave Limb Sounder (MLS) measurements. Mesospheric HO2 is also predicted to be increased by the SPEs, however, the modeled HO2 results are somewhat larger than the MLS measurements. These HOx enhancements led to huge predicted and MLS-measured ozone decreases of greater than 40% throughout most of the northern polar mesosphere during the SPE period. Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) measurements of hydrogen peroxide (H2O2) show increases throughout the stratosphere with highest enhancements of about 60 pptv in the lowermost mesosphere over the 16–18 January 2005 period due to the solar protons. WACCM3 predictions indicate H2O2 enhancements over the same time period of more than twice that amount. Measurements of nitric acid (HNO3) by both MLS and MIPAS show an increase of about 1 ppbv above background levels in the upper stratosphere during 16–29 January 2005. WACCM3 simulations show only minuscule HNO3 changes in the upper stratosphere during this time period. Polar mesospheric enhancements of NOx are computed to be greater than 50 ppbv during the SPE period due to the small loss rates during winter. Computed NOx increases, which were statistically significant at the 95% level, lasted about a month past the SPEs. The SCISAT-1 Atmospheric Chemistry Experiment Fourier Transform Spectrometer NOx measurements and MIPAS NO2 measurements for the polar Northern Hemisphere are in reasonable agreement with these predictions. An extremely large ground level enhancement (GLE) occurred during the SPE period on 20 January 2005. We find that protons of energies 300 to 20 000 MeV, not normally included in our computations, led to enhanced lower stratospheric odd nitrogen concentrations of less than 0.1% as a result of this GLE.

Diffusion analysis of the GLE (ground-level enhancement) of September 29, 1989

1996 ◽  
Vol 74 (5-6) ◽  
pp. 290-294 ◽  
Author(s):  
C. A. de Koning ◽  
T. Mathews
Keyword(s):  
Ground Level ◽  
Mean Free Path ◽  
Isotropic Scattering ◽  
Neutron Monitors ◽  
Ground Level Enhancement ◽  
Diffusion Analysis ◽  
The World ◽  
The Mean ◽  
Power Law Index ◽  
Rigidity Dependence

On September 29, 1989, neutron monitors and muon telescopes around the world recorded a significant increase in their count rate. This ground-level enhancement affords a unique opportunity to study the rigidity dependence of the interplanetary scattering mean free path, [Formula: see text]. By fitting the well-known diffusion model to worldwide neutron monitor and muon telescope data, we calculate the value of [Formula: see text] observed by each station. A plot of [Formula: see text] observed by each station versus the mean rigidity of solar flare particles observed by each station (which ranges from 3–16 GV) clearly indicates that [Formula: see text] is rigidity dependent. If we assume that [Formula: see text] for P > 3 GV, where the power-law index q is a measure of the deviation from isotropic scattering (q = 1), then we find that q = 0.86 ± 0.03 at the time of this ground-level enhancement.

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